Code cleanup: Remove references to IRNodes from SkSLPool.

There is no longer anything IRNode-centric about SkSLPool; it is not
optimized around specific allocation sizes, and could be used to
allocate anything that is associated with a Program. Update comments and
function names to reflect this.

Change-Id: Ica1a78f7415edb25b93a93d00fe54557883c5eed
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/334676
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
3 files changed